Door control mechanism



March 9, 1943.

R. u. SCHNEIDER DOOR CONTROL MECHANISM Filed May 31, 1940 2 Sheets-Sheet 1 March 9, 1943. R. u. SCHNEIDER 2,313,095

DOOR CONTROL MECHANISM Filed May 31, 1940 2 Sheets-Shet 2 Patented Mar. 9, 1943 DOOR CONTROL MECHANISh/L Raymond U. Schneider, Chicago, 111;, assigno'r'to The Guardite Corporation. a corporation of Illinois Application May 31, 1940,. Serial No. 338,210

(c1. zen-s) 8 Claims.

This invention relates to a door control mech anismand more particularly to automatic means of raising and lowering a vertical lift door in connection with a vacuum chamber.

The invention is illustrated in theidrawings in which Fig. l is a frontelevation of; the door; Fig. 2 is a side'elevation thereof; Fig. 3 is a sectional view taken along the line 3-3 in" Fig. 1;

Fig. 4 is a diagrammatic view of the valve control mechanism with the door lowerede-nd in closed position; Fig; 5 is'a similar view-with the door lowered but in open position; Fig; 6 is a similar view with the door raisedand open pand Fig; '7 is a similar view with thedoor raised but about to be lowered by its own weight.

The door is designed primarily for square or rectangular vacuum tanks such as those" employed for treating-tobacco. The end. o-f-such a tank Hi is indicated-inFig. 2: The rectangular opening provided in the end of the chamberis closed by the door il which is of'steel-plate reinforced by suitable cross members l2 and preferably provided with portholes-|3f for inspection of the operation of the tank; The: door is suspended by three cables Hi,- |5 and Cable I5 is attached to a bracket |'|iat the top-of-the door and extends over the sheave-l8 and passes down under the pulley |9 up-over the sheaveZfl and is secured to the adjustable member- 2i which is anchored to the supporting frame 22. The pulley I9 carries a shaft 23 which is connected to the piston 24.0f theair cylinder 25. plied to the upper. part of the cylinder through the opening 26in the customary manner.

Cables I4 and iii are attached to brackets-2l and 28, respectively,.onw the door H, and are passed upwardly over. sheaves 29. and 30 and are secured to a counterweight 3| of somewhat less weight than the door. The sides of. the doorare provided with blocks 32 in which-are. secured shafts 33 carrying rollers which revolve about.

a horizontal axis parallel with thefacefof the door. The rollers 34 are guided by gUideJraiI'. 35 which is pivotally mounted at 3.5,"and an exwith the door originally in raised-position; air is vented from the air cylinder25 whichpermitsthe door to fall of its own weight, it being heavier- Air is supthan the counterweightzifl-e When the door has dropped into position, air is passed into the air cylinder 4| 5 with theiresult that the guide rail 35 is drawn toward the" tank. This pulls the rollers 34 toward the tankand by this means the door ,itself is drawrri-nto close contactwith the tank. i In raising the door the process is repeated, airbe'ing forced into the opposite side of the air cylinder 4| through 'thebopening i3 and thus forcing the door away from the tank. Air is then admitted .to' the air cylinder 25 which lifts the door'to its top position.

IniFigures' 4 to '7, inclusive, a valving arrangement is shown which permits this operation to be carried on witha minimum of manual control.

In: Figure 4 the door is closed. In the control system there is a needle valve 55 which is connected through 'aT 58*With a check valve 5| and a four-way valve 5 2. The manually controlled tour-way master'valve 52 is provided with anexhaust opening 53; an air'supply opening 54,

an opening 55 leading to air cylinder 25, and a fourth opening 56- leading to opening 59 of the automatic four-way valve 51. The other connections in this Valve are an exhaust opening 60, an opening 6|- leading to a second needle valve 62 whichisconnectedthrough a poppet valve 63 with the air cylinder 4| and an opening 64 which is connected through the line 65 of the-opposite side of the air cylinder 4|.

The needle valve is connected by the line 65'with the top of the air'cylinder 25. The T 58 leads through the needle valve to' the 'air' ,air'passes from-59 to and through the line in Figure 5, openings 54 and 55 are connected so-that the air supply is conducted to the T58 andthence flows in" twodirecti-on's through the I needle'valv'e-50 and the check valve 5|.

The capacity of" thef-needle valve being 'quite" small. the first-result i's-for the air to rush through the check valve 5| into the air cylinder 4| and push the door outwardly, the air from the opposite side of the piston being forced out through line 55 and openings: 64, 59, 56 and 53.

The poppet valve 83 automatically closes as soon as the door starts up so that no leakage occurs through this line. However, before the door has started up, there is a negligible leakage of air through the poppet valve 63, the needle valve 62, and the exhaust opening 60.

When the door rises, a spring pressed treadle, which is held down by the weight of the door, opens, thereby permitting the poppet valve 63 to close and also moving the four-way valve 51 to position B. In this position, the line 55exhausts through opening 68, whereas the other relationships are operatively unchanged except that the poppet valve 63 is now closed. The valves remain in this position so long as the door is up; but when it is desired to lower the door the fourway valve 52 is returned to the A position which connects the air cylinder 25 with the exhaust opening 53, permitting the air to exhaust slowly through the needle valve 50. The door control air cylinder 4 I, however, cannot exhaust through the check valve 5|. However, when the door reaches the foot treadle, the four-way valve 57 is returned to the A position, as shown in Figure.

4, and air may then exhaust from the left hand side of the cylinder through the poppet valve 63 which is then open, the needle valve 62, opening El, and exhaust opening 50. At the same time the air supply is connected through openings 54, 56, 59, 84 and the line 65 to the right hand side ofthe cylinder so that the door is forced inwardly.

The arrangement of valves just described automatically raises or lowers the door and moves it into closed or open position merely by moving one valve. This makes it impossible to move the door inwardly while in raised position or to put the connections into an arrangement where the air will move in the wrong direction at the wrong time. The arrangement also moves the door into closed position slowly but moves it into open position rapidly.

The manner in which the valves 51 and 63 are operated by the door is shown in Figs. 4-7, inclusive. In Fig. 4 the door is down and in. In Fig. 5 it is down and out. In Fig. 6 it is up and out. In Fig. '7 it is moving downwardly and is still out. The valve 51 is provided with an operating arm 51a connected by a link 51b to the lever 88 pivoted at 8| and provided with a treadle 82 adapted to be engaged by the door I! in its lowermost position. I 83 indicates a spring normally tending to raise the treadle 82. When the treadle is down, the valve 5'! is moved to the A position as shown in Figs. 4 and 5. When the door is up the spring 83 raises the treadle 82 and lowers the lever 88 to move the valve 51 to the B position as shown in Figs. 6 and 7. The lever 80 is also provided with a projection 88a, adapted to engage the roller 84 on the valve rod 85 controlling the poppet 63 when the lever 80 rises. That is, when the door depresses the treadle 82 and raises the lever 88, the poppet valve 63 is opened as shown in Figs. 4 and 5. When the door rises to release the treadle, the spring 86 on the poppet valve closes the same as shown in Figs. 6 and 7.

81' indicates a check valve in the pipe leading from the automatic valve 5'! to the pipe 61. Air is free to pass through the check valves 5| and 81 in the direction indicated by the arrows but not in the reverse direction. The needle valve has a restricted orifice 50a and the needle valve 62 has a restricted orifice 62a.

As described above, the door H is vertically movable to open or closed position. It is operated by the pneumatic device 25. For convenience, I shall refer to the raising and lowering of the door as opening and closing it. The small cylinders, 4| move the door horizontally inwardly and outwardly. For convenience, I shall refer to this movement as sealing or unsealing the door.

-'I'hat is, when it is moved inwardly it is sealed.

When it is moved outwardly it is unsealed.

The valve 52 is manually controlled. It has two positions--A, the door lowering or closing position, and B, the door opening or raising position. That is, the valve 52 can be operated manually to open or close the door. As shown in Fig. 4, the valve 52 is in door closing position and the door is closed and sealed (moved horizontally inwardly by the cylinders 4|). When the valve 52 is moved to the 18 position, the door is first unsealed and then raised or opened. If the valve B then be moved to A position the door is closed and then sealed.

The foregoing detailed description has been given for cleamess of understanding only, and no unnecessary limitations should be understood therefrom.

What I claim as new, and desire to secure by Letters Patent, is:

1. In combination with a door adapted to be moved vertically between open and closed positions, and horizontally between sealed and unsealed positions, control means, including: a pneumatic device adapted to open or close the door; a pneumatic device adapted to seal or unseal the door; a manually controlled valve for actuating said door opening and closing device, said valve when in door opening position adapted to actuate the door sealing device to move the door to unsealed position; and an automatic valve for operating said door sealing and unsealing device, said automatic valve adapted to be moved to door sealing position by the door whe in its lowermost position.

2. In combination with a door adapted to be moved vertically between open and closed positions, and horizontally between sealed and unsealed positions, said door having suificient weight normally to close by gravity, control means, including: a door opening cylinder; a door sealing and unsealing cylinder; a source of air pressure; and a manually controlled valve adapted to be moved to door opening position to admit air to both cylinders simultaneously, whereby said door will be unsealed and opened, or moved to door closing position, whereby the door opening cylinder will be vented permitting the door to close by gravity.

3. In combination with a door adapted to be moved vertically between open and closed positions, and horizontally between sealed and unsealed ipositions, said door having sufiicient weight normally to close by gravity, control means, including: a door opening cylinder; a door sealingand unsealing cylinder; a source of air pressure; a manually controlled valve adapted to be moved to door opening position to admit air to both cylinders simultaneously, whereby said door will be unsealed and opened, or moved to door closing position, whereby the door opening cylinder will be vented permitting the door to close by gravity; and an automatic valve adapted to be operated by the door when in closed position to admit air under pressure to the sealing cylinder to seal the door.

4. In combination with a door adapted to be moved vertically between open and closed positions, and horizontally between sealed and unsealed positions, said door having sufficient weight normally to close by gravity, control means, including: a door opening cylinder; a door sealing and unsealing cylinder; a source of air pressure; a manually controlled valve adapted to be moved to door opening position to admit air to both cylinders simultaneously, whereby said door will be unsealed and opened, or moved to door closing position, whereby the door opening cylinder will be vented permitting the door to close by gravity; an automatic valve adapted to be operated by the door when in closed position to admit air under pressure to the sealing cylinder to seal the door; and an automatic vent valve for the sealing cylinder adapted to be opened by the door when in its closed position.

5. In combination with a door adapted to be moved vertically between open and closed positions, and horizontally between sealed and unsealed positions, said door having sufficient weight normally to close by gravity, control means, including: a door opening cylinder; a door sealing and unsealing cylinder; a source of air pressure; a manually operated valve adapted to be moved to door opening position to admit air to both cylinders simultaneously, whereby said door will be unsealed and opened, or moved to door closing position, whereby the door opening cylinder will be vented permitting the door to close by gravity; and an automatic mechanism operated by the door when in its closed position to admit air under pressure to the door sealing and unsealing cylinder to seal the door.

6. In combination with a door adapted to be moved vertically between open and closed positions, and horizontally between sealed and unsealed positions, said door having sufiicient weight normally to close by gravity, control means, including: a pneumatic door opening cylinder; a pneumatic door sealing and unsealing cylinder; a source of air pressure; a manually operable valve adapted to be moved between door opening and door closing positions;

and an automatic valve normally in B position and adapted to be moved to A position by the door when the latter is in closed position; said manually operable valve when in door opening position adapted to admit air under pressure to both cylinders to unseal and open the door, said valve in said position operating in conjunction with the automatic valve in A position to vent the sealing cylinder to permit the unsealing operation thereof; said manually controlled valve when in door closing position operating in conjunction with said automatic valve in A position to admit air under pressure to the door sealing device to seal the door.

'7. In combination with a door adapted to be when the latter is in closed position; said manually operable valve when in door opening position adapted to admit air under pressure to both cylinders to unseal and open the door, said valve in said position operating in conjunction with the automatic valve in A position to vent the sealing cylinder to permit the unsealing operation thereof; said manually controlled valve when in door closing position operating in conjunction with said automatic valve in A position to admit air under pressure to the door sealing device to seal the door; and a vent valve for the door sealing cylinder adapted to be operated by the door when in closed position to vent the door sealing cylinder to permit sealing of the door.

8. In combination with a door adapted to be moved vertically between open and closed positions, and horizontally between sealed and unsealed positions, said door having suflicient weight normally to close by gravity, control means, including: a door opening pneumatic cylinder; a door sealing and unsealing pneumatic cylinder with a piston therein connected to the door; a source of air pressure; a manually operable four-way valve connected to the source of air pressure and adapted to be moved between door opening and door closing positions; an automatic four-way valve normally in 13 position having mechanism adapted to be actuated by the door when in closed position to move said valve to A position; an automatic vent valve connected to the door sealing cylinder to permit movement of the piston therein to seal the door, said vent valve being normally closed, said valve having mechanism adapted to be actuated by the door when in closed position to open said valve; and suitable connections whereby said manually operable valve when in door opening position connects said air pressure to the door sealing cylinder and the door opening cylinder to unseal and open the door and vents the door sealing cylinder through the automatic valve in A position to vent the door sealing cylinder to permit unsealing of the door, and said manually operable valve when in door closing position vents the door opening cylinder permitting the door to close by gravity and connects the air pressure through the automatic valve in B position to the door sealing cylinder to unseal the door and through the automatic valve in A position to the sealing cylinder to seal the door.

RAYMOND U. SCHNEIDER. 

